Mechanism for mounting sheet material on backing sheets



Aug. 29, 1950 L. MESTRE 2,520,322 MECHANISM FOR MOUNTING SHEET MATERIAL0N BACKING SHEETS Filed Oct. 25, 1945 s Sheets-Sheet 1 v .36 FIG. 2. 3735 INVENTOR. LU l S M E ST RE HA5 ATTORNE) Aug. 29, 1950 L. MESTRE2,520,322

mzcamusm FOR MOUNTING SHEET MATERIAL on BACKING SHEETS Filed Oct. 23,1945 3 Sheets-Sheet 2 FIG. 3.

' INVENTOR. '75:! LUIS ME STRE HA5 ATTORNEY Aug. 29, 1950 L. MESTRE2,520,322

MECHANISM FOR MOUNTING SHEET MATERIAL 0N BACKING SHEETS 3 Sheets-Sheet 5Filed Oct. 23, 1945 INVENTOR. LU I S M E S T R E HA5 ATTORNEY PatentedAug. 29, 1950 UNITED STATES PATENT OFFICE MECHANISM FOR MOUNTING SHEETMATERIAL ON BACKING SHEETS Luis Mestre, New York, N. Y.

Application October 23, 1945, Serial No. 623,917

7 Claims. (CL 270-58) The present invention relates generally tomechanism for mounting sheets of desired characteristics on backingsheets or the like and more particularly to a machine for automaticallymounting stencil sheets on backing sheets as long as the requisitematerial is supplied.

Heretofore, such mounting of stencil or other sheets on backing sheetshas been effected largely by manual operations. invention all necessaryoperations are carried out automatically and production will beaccelerated substantially.

An important object of the invention is to provide a novel andadvantageous machine adapted to carry out automatically work of thcharacter specified.

Another object of the invention is to provide a novel and advantageousmachine for assembling According to the present and securing togetherpairs of sheets wherein two sheets at least one of which has adhesivematerial at one face thereof are brought edgewis into position one abovethe other but spaced apart and then they are moved into contact witheach other and pressed together to render said adhesive effective.

Still another object of the invention is to provide a machine of thecharacter specified wherein as soon as a sheet is mounted on a backingthe assembled parts are shifted to another position.

Yet another object of the invention is to provide apparatus of thecharacter specified wherein a pile of sheets to be mounted is raised thethickness of a sheet thereon after each removal of a sheet from the topthereof and a pile of backing sheets is raised the thickness of abacking sheet each time a backing sheet is removed from the top thereof.

According to one manner of carrying out the invention, sheets to bemounted such as stencil sheets are supplied in a pile or stack containedin a vertical chute which accurat ly positions the sheets. Said pilerests on a vertically movable table which is moved upwardly a distanceequal to the thickness of one of said sheets. The uppermost sheet isbelow the top of the chute and one of the walls in contact with the endsof the sheets is outturned to support the head or top portion of abaclnng sheet which is longer than the stencil, and then upturned toposition the backing sheet accurately. Each of the backing sheets isprovided at its head or top end with a series of perforations,preferably in the form of keyhole slots, and when a backing sheet is inposition over the pile of stencil sheets said perforations thereof lieabove said shelf and slots therein which extend through said upturnedportion.

At a side of said chut engaging the sides of the stencil sheets, thereis a generally horizontal feed table over which backing sheets arepassed to the top of the stack of stencil sheets. This table is higherthan the uppermost stencil sheet in the stack and between the table andthe top of the stack there is provided a downwardly inclined guide whichmay be formed by properly inclining the corresponding side of the chuteand the table near its adjacent edge. At the outer side of said tablethere is an upright backing sheet chute in which a stack of downwardlyfacing backing sheets is supported with the uppermost backing sheet inposition to be fed edgewise to the feed table. The stack of backingsheets rests on a table in said chute and each time a backing sheet isfed from the top of the stack, this table is raised a distance equal tothe thickness of one of said backing sheets.

Each backing sheet is fed from the top of the stack by a feed devicesynchronized with other parts of the apparatus. Each sheet thus fed tothe top of the feed table is grabbed by upper feed rollers and lowerfeed rollers and fairly thrown along the upper surface of said feedtable intoengagement with the opposite side of the stencil sheet chute.As each backing sheet crosses the feed table, adhesive is applied to itsface along a transverse zone which will li above the adjacent end of theuppermost stencil sheet.

The adhesive on the backing sheet must not engage the adjacent stencilsheet during the travel across the stencilsheet chute. To this endprovision is made of fingers passing through the opposite wall of thechute, projected over the stencil sheet stack to receive the backingsheet thereon and then withdrawing. As soon as said fingers arewithdrawn, a roller is advanced from said opposite side of the chuteover the upper surface of the backing above the zone provided withadhesive and then withdrawn.

As soon as the pasting action is completed, the backing sheet is pickedup by its upper end, carried across the stencil sheet chute anddeposited face up on a vertically-movable inclined table or a stackthereon. The inclination of the table prevents the assembled sheets fromworking outwardly and makes it feasible to use a chute with an openouter side thus facilitating removal of stacked material therein. Thistransfer-of individual sheets with stencil sheets attached thereto maybe effected by means including an oscillating arm swinging about a pivotparallel to the. discharge side of the stencil sheet chute.

Substantially at the time a pasting operation is completed, the free endof the transfer arm is at the opposite side from the pivot.

Pivotally mounted on the free end of the transfer arm is a memberparallel to the axis about which the transfer arm swings and having pinsadapted to enter the slots in the shelf and the large parts of thekeyhole slots and then after passing into the various ends of saidkeyhole filgl 151; the backing sheet and attached 3 stencil sheet, swingthese assembled sheets over to the other side of the stencil sheets anddeposit them on the stack or table at that position. Of course thepositioning of the fingers must be effected by other means.

Other objects, advantages and features will appear upon consideration ofthe following detailed description and of the drawings, in which Fig. 1is a plan view illustrating one embodiment of the invention, parts beingbroken away to show the underlying structure;

Fig. 2 is a section taken along the line 2-2 of Fig. 1;

Fig. 3 is a side elevation of the structure of Fig. l as viewed in thedirection of the arrows at the end of line 33;

Fig. t is a section on the line 1-5 of Fig. 1;

Fig. 5 is a section taken along the line 5-5 of Fig. 3;

Fig. 6 is a fragmentary section taken along the line 66 of Fig. 3;

Fig. 7 is a fragmentary sectional view of the structure at the free endof the transfer arm; and

Fig. 8 is a fragmentary view showing details of structure at the freeend of the transfer arm.

Referring to the drawings, there is illustrated an embodiment of theinvention paticularly adapted to attach stencil sheets H! to backingsheets ll, each of which may be provided at one end with openings l2preferably in the form of keyhole slots. At starting there is a pile orstack of stencil sheets one. platform or table 53 vertically movable ina guide-way or chute l8 having front and rear walls and H5 respectively,and side walls H which maintain the stencil sheets in proper positionone above another. Also at starting there is a pile or stack ofdownwardly facing backin sheets on a platform or table I8 movable in aguideway H].

A backing sheet fl is fed from the top of the stack on table is by meansof a device reciprocating over the top of this stack and comprising oneor more feed rollers 26 resting on the uppermost backing sheet andturning freely in their non-feed movements. These rollers are heldagainst rotation in their opposite or feed movements and in each ofthese movements feed the top backing sheet over an intermediate table 2|to feed rollers 22 which feed the sheet rapidly into position over thestack of stencil sheets it.

In its movement over the table 2! the backing sheet passes beneathrollers 23 and over a roller 24 which dips into a paste receptacle 25and applies a band of paste to theface of the backing sheet near theline of perforations. Rollers 22, and the first roller 23 may be on oneshaft 26 and the paste roller 24 may be on a shaft 21, the shafts 2c and27 being operated at the proper speeds by a motor 28 acting throughsuitable speed reducing means 29. The second roller 23 is also operatedby motor 28.

The rollers 22 throw each backing sheet ongaged thereby to a positionover the stack of stencil sheets, against wall is and between lowerfingers 33 and upper fingers which assist in properly positioning thebacking sheet over the uppermost stencil sheet. Said lower fingersprevent the paste on a backing sheet if from engaging the uppermoststencil sheet as it passes to a position thereover. Said upper fingers 35 are inclined downwardly from their free ends and act to knock down onthe lower fingers 33, each sheet fed thereto by the rollers 22. Thestencil sheets If are shorter than the backing sheets H and the guidewayor chute I4 is correspondingly smaller in horizontal section than theguideway it. The arrangement is such that the bottom end of the backingsheet will be positioned directly over the bottom end of the uppermoststencil sheet and the upper perforated end of the backing sheet willextend beyond the upper end of the top stencil sheet and overlie anarrow horizontal shelf or table 35 having at its outer edge a verticalflange 3t to aid in positioning the backing sheets over the uppermoststencil sheets. As indicated in Figs. 2, 3 and 4, the table 35, the topstencil sheet if) and the fingers 33 are at a lower level than table 2|.It is therefore necessary to have each backing sheet if knocked down byfingers 34. There is a downwardly inclined supporting surface betweenthe table 2! and the top of the wall 55. This inclined support may bedesignated as 2 ia.

At this stage of the operation the backing sheet over the stack ofstencil sheets is supported by the fingers 33 and by the table 35. Thefingers 33 and 34 are then withdrawn and a roller 31 at the free end ofa pivoted arm 38 is moved over the upper surface of the backing sheetabove said band of paste, toward the stack of backing sheets and then inthe opposite direction off the backing sheet. In this reciprocation theband of adhesive material on the backing sheet will be pressed againstthe upper end of the top stencil sheet and the two sheets will be pastedtogether.

The backing sheet with the attached stencil sheet is then picked up byfingers 39 entering certain perforations or openings 12 and movingupwardly through slots 35a in table 35 and communicating slots 36a invertical flange 36. Said fingers 39 are part of a suitable transferdevice adapted to swing the perforated end of the backing sheet over tothe other side of the machine and deposit the assembled sheets in turnedover position on a table 40 movable vertically in a guideway or chute M.Preferably said table 40 is inclined upwardly toward its outer edge andthe chute 4| is open at the corresponding side, thus facilitatingremoval of the mounted sheets. The fingers 33 and 34 are then returnedto their positions over the stack of stencil sheets preparatory toreceiving another backing sheet.

The operations thus described in general for a single backing sheet anda corresponding stencil sheet will be repeated until it becomesappropriate to replenish the stack of backing sheets and/or stencilsheets, or to stop the machine for other reasons. In this connection itmay be said that the hacking sheet table I 8 and the stencil sheet tableI 3 are moved upwardly during the operation of the machine and the table4'!) is moved downwardly, to maintain the tops of the stacks or piles atthe proper levels.

The feed rollers 22 are rotated at high speed and throw a sheet advancedthereto, into position over the stack of stencil sheets and between saidlower fingers 33 and upper fingers 34 which are positioned over thestencil sheet stack at that time. It will be evident therefore thatfeeding of the backing sheets to the stencil sheet stack at proper timesdepends upon proper timing of the feed by the feed rollers 29. Saidrollers 20 have friction surfaces which may be of rubber and are mountedon a shaft 42 to which they are connected by one way clutch mechanismwhich may be of known construction. This shaft 22 may have its endsfixed in sides 43 of a Ushaped frame at the end of an arm 44 projectingfrom a shaft carried by arms 46 pivoted at 41 on frame members 48 atopposite sides of the frame. This backing sheet feed mechanism issubstantially the same as mechanism heretofore in use. An example ofthis feed mechanism is shown in my prior Patent No. 2,233,895, March l,1939.

In the machine herein disclosed the arms 4'5 are swung about theirpivots ll by means including an arm 49 constituting a downward extensionof one of said arms 46 and having at its lower end a pin-and-slotconnection with one end of a forwardly and rearwardly extending link 50mounted for longitudinal movement. At its other or rear end, the link isconnectedby a short link 5| to again 52 eccentrically mounted on avertical shaft 53 as by means of an arm E i fixed on the lower end ofsaid shaft.

The shaft 53 is driven by means including a bevel gear 55 fixed thereonand meshing with a bevel gear 56 at the rear end of a horizontal shaft51 which as brought out more fully hereinaftermay be considered the mainshaft of the machine. Fixed on said shaft is a grooved pulley 58 whichis connected by means of. a suitable belt 59 to a smaller grooved pulleydriven by a motor 6! mounted in the lower part of said frame. The beltand pulley construction just described constitutes speed reducing meansand a speed reducer 62 may be interposed between the motor 6| and pulley60.

The link 58 may also be utilised to raise the stencil sheet table [3 andthe backing sheet table I8, and lower the table All on which the backingsheets with attached stencil sheets are deposited. Each of said tablesis supportedby means inelud ing a vertical member 63 having its upperend secured to the bottom of the table and having an axialscrew-threaded bore receiving a rotatable externally screw-threadedmember 54 which is supported by the frame of the machine againstdownward movement. Each member 63 may be held against turning about itsvertical axis as by making it with a square, external cross section andslidable through a square hole in a fixed member.

Fixed on each externally screw threaded mem ber 64 is a ratchet wheel 55operable by a pawl :35 pivoted on an arm 6'! mounted to swing about theaxis of said member 5t. Each arm 6? is operated by means of a link 58pivoted at one end to said arm and at the other end to link 5?. Thedrivingof the ratchet wheel 555 may be regulated by means of apin-:and-slot connection between arm 61 and link 58. It will be seenhowever, that with the disclosure in Fig. 6, the screw threads of thesupporting members for table n! would have to be in a direction oppositeto those for the other tables in order to lower it concomitantly withthe raising of the other tables. The different rates of feed for thedifferent tables may be provided for in various ways, for example byusing screws of different pitch or by giving different movements to thearms carrying the pawls.

The vertical shaft 53 is connected at its top, by a bevel gearconnectionutsa, to a transverse horizontal shaft 69 which serves throughsuitable intermediate means to reciprocate thelower fingers 33, theupper fingers 3t, and the roller 3'! which completes the pasting of thestencil sheets to the backing sheet. The lower fingers 33 are attachedat one end to a transverse bar or member 10 at the bottom thereof andthe upper fingers 34 are attached to said bar at the top there of.Grooved wheels ll are pivoted onopposite ends 'of said bar 19 and runbetween pairs of. rods 72 supported at opposite ends in the frame. Of

.the fingers 33 and 34' the lower fingers 33 extend through openings ina plate 73 carried b the frame at the rear of the guideway for thestencil sheets.

The upper fingers 34 which turn upwardly toward their forward ends passthrough notches or cut-outs in the upper part of said plate 73. Suchupward turning of fingers 3d assures the entrance of a backing sheetbetween the sets of fingers, directs the sheet downwardly, and alsoexerts a checking action on sheets fedthereto by the feed rollers 22.

The bar 10 may be reciprocated along said rods or guides 12 by means ofa link 14 pivoted at one end to the bar 10 at its middle and at theother end to the upper end of a lever 15 of which the lower end ispivoted on a cross shaft 15a of the machine. The lever '15 is actuatedthrough a link is pivotally attached to the lever at an intermediatepoint thereof and pivotally attached to the lower end of a lever llpivoted at its upper end to thefixed frame. As illustrated, the lever T!is offset at its middle portion to extend around the shaft 69 and thuseconomize space. Mounted on said shaft 69 is a cam disk is having at oneface a suitable cam groove 19 to receive a cam follower or pin 86projecting from the side of the lever Tl. i

The arm 38 carrying the roller 31 at one end extends through an openingin plate l3: and is connected at its other end to a member 82 providedat its ends with grooved wheels 83 engaged by rods 84 above and belowthe same to provide guideways therefor. Thismember 82 may also bereciprocated by a link M, a lever 15 pivotally mounted on cross shaft15a, a link 16, a lever H, a cam disk 18a on shaft 59 and having asuitable cam groove lilo, and a cam follower or pin 83a. The cam groove59a is so shaped that the roller 31 is not moved over the backing sheetuntil the latter has been placed over the stencil sheet stack betweenthe upper and lower fingers 33 and 34 respectively and said fingers havebeen withdrawn. After completing this movement the roller 31 isretracted.

The shaft 5! which has at its rear end a driving connection with saidvertical shaft 53, is supported in suitable bearings 85 and near itsforward end it carries an eccentric pin 85 as by means of an arm 81mounted firmly on the end of the shaft.

Said eccentric pin 85 is utilized for operating mechanism by which eachunit consisting of a backing sheet and a stencil sheet pasted thereto.is swung from the top of the stencilsheet stack and deposited faceupward on the platform or table 48. To this end the pin as projects intoa radial slot 88 in a member or arm 89 projecting downwardly from ashaft 99 on which it is fixed.

As illustrated the axes of the shafts 51 and 9!] (Fig. 5) are paralleland located in the same vertical plane. is rocked about its axis. Thisrocking movement is transmitted from shaft 90 to a shaft 9! directlyabove the same by means of a gear 92 on shaft 93 and a smaller gear 93on shaft9 l. Fixed on the shaft 9! is a transfer arm or frame 94 whichis swung back and forth between an upright position above shaft 9! and agenerally horizontal position across the machine. Said transfer frame 94may take many different forms but as shown in its pickup position (Fig.5) has a straight top portion 95 extending across the As the shaft 5'!turns, the shaft 96.

machine, an end portion 96 extending downwardly to shaft 9I to which itis fixed, and at the opposite end a downwardly extending end portion 91to carry a suitable device including said fingers 39, for picking upbacking sheets to which stencil sheets have been pasted.

Said fingers 39 are carried by a sleeve 98 mounted on a rod or shaft 99projecting from the free end of end portion 91 of th transfer frame 94.Said sleeve 98 may be held by any suitable means against movement offthe end of said rod .99. As illustrated the fingers 39 comprise arms Iprojecting from said sleeve and pins IOI projecting from said arms I00and "coaxial therewith. Extending from said sleeve 98 at the sideopposite to said fingers 39 is an arm I02 carrying a counterweight I03projecting from the side thereof and preferably cylindrical in shape.

Normally said counterweight I03 will act on saidsleeve 98 to hold an armI04 projecting therefrom against a pin I05 at the right in Fig. 5, asindicated in dot-and-dash lines directly above the stencil sheet stack.This pin I05 projects from a plate I03 fixed on the free end of portion91 of the transfer frame or arm. Said plate I06 is shown in completeform in Fig. 8 and in other figures as partially broken away. Rockingmovementof said sleeve 98 to swing said arm I04 away from said pin I 05is limited to prevent overthrow, by engagement of arm I04 with a pin I01corresponding to pin I05. Also fixed on said sleeve is the base portionH08 of an arm I09 having an end part or flap IIO (Fig. '7) hinged atpivot III to said base portion or base I08. This hingeis constructed sothat flap I I0 cannot be turned counterclockwise (Fig. 5) beyond thestraight line position with reference to base portion I08. The flap can,however, be turned in the opposite direction about said pivot againstthe action of a spring I I2.

As the transfer frame swings downwardly in the clockwise direction (Fig.5) the fiap H9 moves downwardly along the outer arcuate surfaceof aguide I I3. During the movement alon said arcuate surface the flap IIIis held away therefrom until, as the transfer frame reaches itslowermost position, the counterweight I08 engages a concavely curvedupper surface of a cam IM and the arm I04 is swung counterclockwisetoward pin I97 on plate I06. As the arm IE4 comes close to the pin I01,the transfer frame reaches the lower limit of its movement and furthermovement of arm I04 toward pin I0! will be overthrown due to inertia.

However, as the sleeve 98 moves in counterclockwise direction (Fig. 5)at this time, said flap H0 will engage 'said arcuate surface of guide II 9 and be turned back until it passes the lower end of said guide andsnaps to its original position with reference to the base portion I08 ofarm I09. Then on the upward movement of the transfer frame, the flaprides along said arcuate surface and keeps the fingers 39 insubstantially their leftward limiting positions with arm I0 3 againstpin I01 until the flap passes off the upper end of the guide. Duringthis movement the pins IiiI at the outer ends of fingers 39 passupwardly through the slots in the table 35 and vertical flange 38 andthe points of the pins enter the large ends of the keyhole slots in thebacking sheet over the stencil sheet stack. As the pins rise theinclined body portions eventually engage the ends of the narrow portionsof the slots and then lift the righthand end of the backing sheet andthe-attached stencil sheet.

As the flap I I0 moves off the upper end of guide II3, the sleeve 98 isturned clockwise (Fig. .5) by the counterweight I03 until arm I04strikes pin I05 on said plate I06. The backing sheet and attachedstencil sheet are swung upwardly about the left edge of the backingsheet as indicated by the intermediate position (Fig. 5) of the transferframe. As the transfer frame approaches the left end of its path, theflap I I0 strikes the upper end of a trip member II5. Such engagementcauses sleeve 98 to be turned in a counterclockwise direction. Themovement of the transfer frame is halted before the arm I04 engages pinI0! but the momentum of the swinging parts causes the arm I04 to swinginto position against the pin 801. At this stage the pins 'I 0 I arepointed downwardly so that the backing sheet transferred thereby isfreed and swings downwardly and to the left until it falls on the stackcarried by table 40.

It should be understood that various changes may be made and thatcertain features may be used without others, without departing .from'thetrue scope and spirit of the invention.

What I claim is:

1. In a machine of the character specified, means for supplying insuccession at a predetermined position single sheets to be backed, meansfor supplying backing sheets in succession at a second predeterminedposition, means for applying adhesive to one of two sheets to beassembled and superimposing the two sheets by relative edgewise movementthereof, means for preventing during such relative edgewise movementcontact of adhesive on one sheet with the other sheet and means forpressing the two sheets together to render the adhesive effective, meansfor removing each pair of attached sheets, turning it over anddelivering it at a predetermined position, said last-mentioned meansincluding sheet-holding means supported to travel in an orbit whichtraverses one edge of the attached sheets assembly and substantiallyabout the other edge of said assembly as an axis, and means forrendering said sheet-holding means effective at said first-mentionededge.

2. In apparatus for successively mounting sheets on longer backingsheets, a vertical chute containing a pile of downward facing sheets tobe mounted, means including a table supporting said pile of sheets forraising said pile when sheets are removed from the top thereof, meansfor feeding backing sheets one by one edgewise to a position over saidpile, means in the feed path of said'backing sheet for applying adhesivethereto along a transverse zone near its upper end, means for spacingsaid backing sheet from said pile while moving it to overlie said pileand then dropping it on the uppermost sheet of said pile with theadhesive over the upper end of the sheet, means for pressing eachbacking sheet against the top sheet of said pipe to render the adhesiveeffective, means to receive backing sheets on which other sheets havebeen fastened, and means effestive when a backing and other sheet havebeen fastened together to pick up the exposed head end of said backingsheet and by turning the backing sheet around its lower edge deposit theunited sheets in inverted condition in such receiving means, saidlast-mentioned means including sheet holding means supported to travelin an orbit which traverses one edge of the attached sheets assembly andsubstantially about the other edge of said assembly as an axis, and

means for rendering said sheet-holding means effective at saidfirst-mentioned edge.

3. In apparatus for assembling with backing sheets other sheetsrequiring backing, comprising means for supporting in registration apile of sheets to be backed, means for feeding backing sheets one by oneedgewise to a position over said pile, means in the feed path of saidbacking sheet for applying adhesive to the underside of each sheet alonga transverse zone near its upper end, means for directing said sheetdownwardly over said pile, means under said directing means for spacingsaid backing sheet from said pile, in a position overlying the samecomprising supporting fingers movable longitudinally in one direction ina horizontal plane to a position to prevent contact of the adhesive withthe sheet to be mounted during the feeding movement and in the oppositedirection to permit said backing sheet to fall into contact with the topsheet of said pile, means for pressing each backing sheet against thetop sheet of said pile to unite the two sheets, and means to remove fromthe top of said pile each pair of attached sheets, said last-mentionedmeans including sheet-holding means supported to travel in an orbitwhich traverses one edge of the attached sheets assembly andsubstantially about the other edge of said assembly as an axis, andmeans for rendering said sheet-holding means effective at saidfirst-mentioned edge.

l. In apparatus of the class described, a vertical chute containing apile of sheets to be backed, the side of the chute at one end of theuppermost sheet being oifset to form a horizontal shelf to receive thehead end of a backing sheet of greater length than the sheets in saidchute and attached to the adjacent end of the uppermost sheet andupturned at the outer side of said shelf to position the correspondingend of a backing sheet, said backing sheet having a line of perforationsover said shelf and said shelf and upturned portion having communicatingslots corresponding in position to said perforations, and means to pickup the perforated end of said backing sheet and deposit it in turnedover position at the opposite side of said chute comprising an armoscillating about an aXis at the opposite side of the chute and carryingat its opposite end a device adapted to rock about an axis parallel tosaid axis of oscillation, said device having pins to enter saidperforations, and means to control said device to hold said pins awayfrom the perforated end of the backing sheet in its downward movementand to cause said pins to enter said perforations in the reversemovement to carry the backing sheet over to the other side and thenrelease the same.

5. In apparatus of the class described, a vertical chute holding invertical alignment a pile of horizontally positioned sheets to bebacked, a table at the foot of said pile and means for raising saidtable the thickness of one sheet after an uppermost sheet has beenremoved, the uppermost sheet being below the top of the chute, the chutewall at one end of said sheets extending outwardly at the level of'saidpile to form a shelf to support the head end of a backing sheet ofgreater length than the sheets in the pile and an upright end todetermine the position of the corresponding end of a backing sheet,means for attaching the end of said uppermost sheet to said backingsheet, each of said backing sheets having a row of openings in the partover the shelf and said shelf and said upright having connected slots.

6. The combination according to claim 3 wherein the means forpositioning the backing sheet including a second set of fingers abovethe supporting fingers and movable back and forth therewith, saidfingers of the second set being flared upwardly from the supportingfingers to direct the advancing backing sheets down to the supportingfingers.

7. In apparatus of the class specified, a chute containing a pile ofsheets to be backed, a support for said pile, means for raising saidsupport each time an uppermost sheet is removed, a chute wall having anoffset to act as a guide for the extended end of a backing sheet ofgreater length, means for supplying at the top of said chute a backingsheet with a band of adhesive on its lower face and near its head andpressing means to render said adhesive effective to unit said sheets,said offset portion being slotted to its upper edge, and means forremoving the pair of united sheets and depositing it in invertedcondition at another position, comprising a pick-up device and means torender said pick-up device effective to pick up the projecting end ofthe backing sheet at said slotted offset portion and to render saidpick-up device ineffective as the united sheets approach the depositposition.

LUIS MESTRE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,440,856 Westcott Jan. 2, 19231,893,523 Radzinsky Jan. 10, 1933 2,164,371 Ajello July 4, 19392,166,388 Bergstein July 18, 1939 2,260,540 Schramm Oct. 28, 19412,384,768 Rau Sept. 11, 1945

